Extract Fumes into Dryer Vent?

[Proxy]

Hello,

I want to add a fume extractor hood to our e-lab to vent the fumes outside.
It would be simplest to tap into the dryer vent which runs across the ceiling of the e-lab.
If I put in valves in the dryer vent so the solder fumes don't backflow into the dryer will this work? Is it a good/bad idea?

Cheers!

[Geoff]

Does the cost of adding a second vent exceed the cost of adding valves etc. and the risk of a failure contaminating your things? And what price do you put on any peace of mind in keeping it separate?

 

[Mattylad]

I'd be more concerned with the dryer venting into your elab, there is plenty of moisture coming out of those things.

[Proxy]

Yeah we'd have to put in backflow preventers both ways

[nanofrog]

With the backflow preventers in place, yes (in terms of the plumbing).

The real trick IMHO is to make sure the fan you use can generate enough static pressure on the exhaust side. Using some sort of flexible intake duct will reduce the fan requirements vs. what would be required for a range hood (assumes same duct lengths), as it doesn't have to draw in a lot of additional free air just to draw in the fumes at a sufficient rate to keep them out of your face.

[ChuckDarwin]

- If you want to be code compliant (USA) [select icon:         ], dryer vents shall be independent of all other systems and convey moisture to the ouside of the structure.
- The dryer vent is likley coated with lint and it will receive moist air when the dryer is running.  Depending on your fume compositions, the trapped lint could start to smell pretty bad and could also trap acids which will corrode the vent if it is metalic.
- If you use the dryer venting, think about ensuring there is no back-flow, install a damper/diverter, and ensure that the vent termination can't get blocked--such as a lint-filled grill at the terminus.  Clean the vent  out every now and then (robot project).
- If you don't want to run large ducting, transition the extractor duct into a smaller duct that uses a replacable, higher velocity in-line fan.
[corrected typos]

[Proxy]

Code compliance might actually be an issue since we get random fire marshal inspections.

[cdev]

I would look into a heat recovery ventilator which is a balanced pair of fans (one in, one out) with an (usually X oriented)  heat exchanger between them.
They allow ventilation year round. You can site its return i.e. exhaust(s) near your workbench(s).